Hey, this is my first post!
Part of understanding the minimal plot is understanding the world. At least, this is how I see it. You don’t try to avert some kind of catastrophe. The world has already gone to hell and is ruled by demons. The minimal plot basically arises from this premise, and the game is all about setting a particular mood and athmosphere of despair, hopelessness, alienation, where basically every step might mean death. And the difficulty level is intrinsic in achieving this - it’s not a very nice place to be, and surviving is really a feat on its own. It is sort of like a nightmare simulator, so walking about guessing alittle only serves to support this feeling of desolation. There is a story (and I think a damn good one), and you piece it together as you go, but it requires some effort. It is sort of told through the lore and you are given lots of clues, from NPCs, item descriptions or just the world itself, but you need to keep your eyes open and fit all the pieces together.
Hmm, I see now that DeepO basically said the same thing. But I really can't scrap my first post like this, so here goes!